Date: 2025-12-16

http://www.memcached.org/files/memcached-1.6.40.tar.gz

This release includes a large internal refactor of the protocol handling code. This fixes a few corner cases and potential bugs, but please exercise caution as the amount of code changed is large.

Prior to this change the proxy and internal code had entirely separate protocol parsing code. This is now a single code path. Performance should be nearly identical, possibly a very small amount faster as the new code does not modify the request string as it parses.

This release also includes a number of small or obscure fixes, plus some small performance improvements for the proxy code.

• Reload TLS certificates on SIGHUP
• tests: fix race condition in slab mover test
• extstore: fix internal item flag loss on flush
• core: fix worker_logbuf_size start option
• proxy: remove buffer memory limit lock
• proxy: update backend logging options on reload
• slabs: fix page mover busy sleep backoff, add counter
• docs: info for listeners to help string
• core: fix verbose logging in get
• Fix format specifier for nums_napi_id
• extstore: fix start arg issue with page size
• proxy: add some inspection commands for req/res
• proxy: add tracebacks to lua errors in some cases

New feature for the meta protocol:

If a CAS value is suppled with mg, changes the behavior of the ‘v’ flag. If CAS matches, value with not be returned (HD), if CAS does not match, value will be returned. This can be useful for checking if a tiered cache needs to be refreshed.

The following people contributed to this release since 1.6.39.

Note that this is based on who contributed changes, not how they were done. In many cases, a code snippet on the mailing list or a bug report ended up as a commit with your name on it.

Note that this is just a summary of how many changes each person made which doesn’t necessarily reflect how significant each change was. For details on what led up into a branch, either grab the git repo and look at the output of git log 1.6.39..1.6.40 or use a web view.

• Repo list: https://github.com/memcached/memcached/wiki/DevelopmentRepos
• Web View: http://github.com/memcached/memcached/commits/1.6.40

    15	dormando
     1	Aleksandr
     1	Aswath Ilangovan
     1	Yufei Hu
     1	sshetty